CDK2 and granular cell tumor: Upregulation of CCND in response to CDK4/6 inhibition has been shown in several publications and was linked to acquired resistance by bypassing cytostasis via a CyclinD1-CDK2-mediated S-phase entry.12,44,45 GCT cell lines seem to bypass this mechanism as GCT cell lines predominately accumulated in the G1/G0 phase of the cell cycle after PaRi treatment and neither upregulated CyclinD1/2 on protein level nor significantly upregulated CDK2 on RNA level (Supplementary Fig. S7C, Supplementary data S1B).